Historically, fruits and vegetables have been sorted by hand in accordance with predetermined criteria which established several quality grades. The price of the fruits and vegetables would then be established in accordance with such grades. Such a hand sorting process, however, is labor-intensive and hence costly.
Mechanical/optical systems have been developed to provide an automatic grading/sorting capability for fruits and vegetables, based on information provided by a sensing part of the automatic system. Gradually, such systems have become more sophisticated and accurate. In one such system, a conveyor carries the articles to be sorted through a viewing station at which a camera is mounted, typically above the conveyor, in such a manner that the articles are scanned as they pass beneath the camera.
The conveyor comprises a series of roller assemblies which are connected together with a drive chain, but are also individually driven so that they rotate as the conveyor moves longitudinally. This results in the articles on the conveyor moving and rotating, which moves the articles into the valleys formed by the roller assemblies and aligns them on their horizontal axes as they are being scanned by the camera, providing a complete view of the passing articles.
The image produced by the camera is then directed to a central processing unit which analyzes the images of the individual articles in accordance with selected criteria, including size (i.e. length), diameter, volume, appearance and imperfections (rot, cracks and damage). The resulting process data about the articles is then compared against pre-selected standards, and the articles are sorted (or discarded) accordingly. Such a system is disclosed in a co-pending U.S. patent application titled: "Apparatus and Method for Grading Articles", assigned to the same assignee as the present invention. The present invention is directed toward improvements in such previous systems.